I. Field of the Invention
This invention relates generally to a method and apparatus for removing a fluid from or injecting a fluid into a container, and more particularly to a new method and apparatus for removing coolant from and installing coolant into an internal combustion engine radiator.
II. Prior Art and Other Considerations
Studies show that over-heating is a major cause of vehicle breakdowns on highways. Engine cooling systems must operate efficiently at all times to avoid costly repairs that result from excessive temperature. In this regard, cooling systems contaminated by rust, scale build-up and sludge cannot provide adequate heat transfer and cooling system efficiency; in addition, thermostats fail to open, hoses deteriorate, impellers bind or break-off and engine blocks can become distorted or cracked. Accordingly, there is a need for efficient engine cooling system flushing methods and apparatus; however, flushing of such systems in the past required draining of the removed liquid to sewer or waste lines, which was environmentally objectionable. Accordingly, need had developed for apparatus and method to clean engine coolant systems without such drainage. No way was known for accomplishing this objective in the usually advantageous manner as is now provided by this invention.
Many motor vehicles have a water circulation system comprising a radiator, engine block and heater. Many problems are caused by the accumulation of debris in the form of rust or scale or other deposits in the system which impede the flow of the water and the conduction of heat. In the engine block itself the deposits may lead to the build-up of excessive heat and consequently to undue wear or even failure of certain components. Much the same may happen if the deposits clog the radiator or the heater.
To prevent the accumulation of deposits it is known to drain and flush the water circulation system from time to time. Flushing generally take place by opening the system at a low point to allow drainage of water through the engine block or heater, and the pressure of the flushing water is low. Flushing agents which tend to remove deposits from the walls of the passages making up the system are sometimes used to enhance the effectiveness.
A further complication is the presence of the customary thermostat in one of the conduits connecting the engine to the radiator. At the temperature of water for flushing supplied from the mains, the thermostat will normally be closed and will impede effective flushing. Removal of the thermostat may assist flushing, but substantially increases the laboriousness of the flushing operation.
Moreover, todays automobiles having high tech sophisticated computerized engines require proper maintenance of their cooling system. These automobiles have many sensors and switches which operate by sensing the temperature of the coolant in the cooling system. They perform many functions, such as controlling valves, solenoids and cooling fans, etc. Sensors also supply the on board computers with the engine temperature at the different stages of operation. The computer uses this information along with much more to control fuel injection, engine timing, engine idle, etc.
A consequence of these difficulties and complexities is that effective flushing is seldom carried out in routine maintenance of motor vehicles and similar machine having cooling systems, and as a result much engine wear--sometimes computed at more that 50%--is caused by poor circulation of cooling water; and if cooling systems are not properly maintained, many areas of engine control can be affected, such as performance, exhaust emissions, and fuel mileage.
Vehicle manufactures typically advise owners of their vehicles to change the antifreeze in the cooling systems of these vehicles every two years, in order to prevent the accumulation of corrosion materials, such as rust and solder corrosion residue. The corrosion materials are formed as the corrosion inhibitors in antifreeze break down from heat over time. These corrosion materials reduce cooling system efficiency by interfering with the flow of coolant through the air/liquid heat exchanging fin-tubes of the radiator core. An effective cooling system is not only important for engine performance and life, but in many automobiles the transmission fluid is also cooled by circulation through the radiator. Further, the abrasive nature of the suspended corrosive materials increases the wear on water pump, hoses, thermostat, and heater core--and malfunction of cooling system components is said to be the number one cause of highway breakdowns.
Accordingly, there are certainly good reasons why the vehicle makers' recommendation that the old coolant be flushed out and replaced with fresh coolant every two years should be followed. However, industry data indicates that most (about 78%) of the antifreeze sold every year is sold to do-it-yourselfers. And, only 30% of these buyers say that they change their antifreeze regularly, instead of just adding more when needed. Moreover, it is likely that many within this 30% who say that they change their antifreeze are, in fact, only removing the old coolant and corrosion materials from the radiator, and not from the whole system.
To properly change the coolant in a vehicle cooling system, it is not only necessary to drain and flush out the radiator (which normally contains 40% to 50% of the coolant in the system), but it is also necessary to drain and flush out the engine block, heater core and connecting hoses, since the remainder of the coolant is in those areas. Draining and flushing of the radiator does not drain or flush the coolant from the engine block, heater and the connecting hoses, because the flow of coolant from the latter areas to the radiator is block by the thermostat, which is closed unless the system is at operating temperature. Opening up a cooling system which is closed and at operating temperature is not advisable because, in this state, the system is pressurized and opening it may result in hot coolant being sprayed on the operator. Thus, coolant changes should begin only with cold systems, but when the system is not pressurized, the thermostat is closed, and the flow of coolant from engine, heater and hoses to the radiator is blocked. As a result, those car owners who prudently start with a cold system and drain just the radiator are removing only the 40% to 50% of used coolant and suspended corrosion which is contained in the radiator, leaving the remainder in the rest of the system.
There are presently three general approaches an individual vehicle owner may follow to drain and flush old coolant and corrosion from the entire cooling system--not just the radiator. All have their drawbacks.
Consider first the continuous flushing technique utilized by some professional equipment, and some kits sold for do-it-yourself use [an example is a kit sold by First Brands Corporation (PRESTONE) under its trademark "FLUSH'N FILL"]. With this technique, a sealed connection must be made by installing a garden hose-coupled inlet tee ("T") in the cooling system. This is accomplished by cutting into a heater hose and installing the inlet "T" between the severed hose ends. With the radiator drain cock open, the radiator cap off, and the engine running (to keep the thermostat open), water is continuously admitted through the inlet "T" and circulated by the water pump, displacing old coolant which discharges through the radiator drain and the radiator cap neck. After a sufficient period of time, drainage clarity indicates that old coolant and corrosion have been displaced by clean water.
For a person who is not a mechanic, utilizing this continuous flushing approach presents a number of problems:
(1) Installing the inlet "T" requires that the correct hose and installation point be identified, that the reinforced hose be cut and that the "T" be properly installed so that it does not leak (the FLUSH'N FILL instructions recommend consulting a qualified mechanic if unsure).
(2) The approach generates a relatively large volume of waste liquid (up to 700% of cooling system capacity) flowing from both the radiator neck and the drain. This waste liquid is difficult to contain and usually is left to splash on the vehicle and the ground. Since antifreeze is composed largely of ethylene glycol, which is harmful or fatal if swallowed and is poisonous to animals, this method creates a hazardous environmental condition.
(3) The drain cock on the radiator must be opened and closed, respectively, before and after the operation.
Professional flushing equipment designed to contain waste coolant and flush liquid requires at least one additional sealed connection to be made to the cooling system, for purposes of conveying waster liquid out as flushing liquid is pumped into the system. This, of course, adds to both the cost and complexity of use of such systems.
A second method which may be used involves opening up the system at multiple points. With this approach the thermostat, heater hose and the lower engine-to-radiator hose are removed, and the drain cocks on the engine and the radiator are opened. It is then possible to flush water through the various parts of the system without the need to install a permanent inlet "T" or run the engine to keep the thermostat open. However, there are also problems with this approach.
Consider first the draining of old coolant and flush water from the radiator. The radiator can be drained by either opening the drain cock located on the engine side of the radiator near the bottom or by removing the bottom radiator to-engine hose, which is also located on the engine side of the radiator near the bottom of the radiator. (For complete flushing, the drain cock would be opened and the hose would be removed.) For a person who is not a mechanic, performing the seemingly simple task involves a number of practical difficulties:
(1) Either opening the drain cock or removing the bottom hose frequently requires the operator to get under the car, because there is insufficient room in the engine compartment: to pull hard enough on the bottom hose to remove it from the radiator mounting tube without damaging it or causing injury; or to use a wrench on the drain cock handle, which is intended for hand turning but frequently is stuck so tight by corrosion that it requires a wrench. Many automobiles do not have sufficient clearance to permit the operator to perform either of these operations without jacking up the car, with attendant danger.
(2) Use of a wrench on the handle of a drain cock stuck by corrosion involves a substantial risk of breakage, requiring either a difficult replacement of the drain cock or the more expensive replacement of the entire radiator.
(3) Even with the retaining clamp removed, radiator hoses frequently adhere so tenaciously to the radiator hose mounting tube (which, like the radiator itself, is made of light gauge, soft metal), that it is necessary to either cut the hose off the tube or to use a screwdriver or pry bar to push the hose off the tube. If cut, the hose must be replaced, and either cutting or prying the hose risks damage to the mounting tube itself, which again could result in the need to replace the radiator.
(4) Immediately upon opening the drain cock or hose, used coolant flows out, frequently resulting in both the operator and the ground being covered by the used coolant before a receptacle can be used to collect it.
Draining coolant and flush water from the engine block, the heater and the connecting hoses is an even greater problem:
(1) Engine drain cocks are generally even more difficult to access through the engine compartment that radiator drain cocks, and they more frequently require the operator to jack-up and get under the car to open and close them.
(2) Removal of the thermostat requires: unbolting a housing from the engine block; prying the thermostat loose from its gasket, and sealant upon re-mounting of the thermostat.
(3) Removal of heater hoses presents the same type of difficulties encountered in removing engine-to-radiator hoses, and replacement of the two heater hoses (which are very similar in appearance) in their proper location is an added problem.
(4) With the system open at many points for flushing purposes, it is difficult to collect the waste and flush water exiting these many openings when flush water is injected.
The third method of draining and flushing the entire cooling system involves repeatedly draining the radiator, refilling it with water, and running the engine to normal operating temperature. This causes the thermostat to open and permits the coolant previously trapped in the engine, heater and hoses to mix with the clean water added to the radiator. Because in a typical cooling system the water pump has the capacity to turn over many times the total system capacity every minute, and the thermostat, when open, will likewise permit many time the system capacity to circulate to the radiator each minute, the fresh water is quickly and thoroughly mixed with the remaining used coolant.
By repeating the sequence of steps, the amount of old coolant and corrosion remaining in the system can be reduced by approximately one-half each time the radiator is emptied. Thus, the first time the radiator is emptied, approximately one-half of the used coolant in the system is removed. After running the engine to mix the remaining used coolant with the fresh water, draining of the radiator reduces the remaining used coolant to one-quarter of that initially contained in the cooling system. The third repetition reduces it to one-eighth; the fourth to one-sixteenth, etc.
In this way, the operator can flush a high percentage of the total old coolant and corrosion from his entire cooling system (not just the radiator) without the need to open drain cocks or hose connections on the engine. While mechanically simpler, however, this method nevertheless requires a great deal of physical labor. The operator must get under the automobile several times to open and close the radiator drain cock, or to remove and replace the bottom radiator-to-engine hose, whichever draining procedure is being used. Also, if the car has to be jacked up to take these actions it would have to be let down each time in order to run the engine. Thus, for example, to flush at least 87.5% of the old coolant from the system requires that the radiator be drained three times, which would require that the operator get under the automobile six times (three times to open the draining point and three more times to close the draining point). Further, after the first engine warm-up to open the thermostat, the operator would either have to open the drainage point on a hot radiator or wait some period of time for the system to cool down before proceeding.
Although a pump could be utilized to drain the radiator, in order to avoid the need to repeatedly open and close the drain cock, most automobile owners could not justify the cost of such a pump, nor would they be willing to undertake the storage and maintenance of such a pump.
Prior art devices are designed to remove fluids for disposal or to treat them and then return the fluids back into the system at the time the equipment is attached. These inventions do not have the capability of removing, containing, storing and reinstalling the fluids at a later time without the necessity of special adaption or modification to the cooling system.
Accordingly, while there are clearly good reason to flush out and recharge cooling systems in accordance with the vehicle maker's recommendations, many car owners do not do so because of the attendant difficulty of the task. Therefore, there are a great number of vehicles that are not serviced as they should be, with the associated high costs of: (1) poorer performance and more frequent maintenance; (2) shortened engine life; and (3) more frequent highway break down. Such costs could be reduced by providing a way for individual vehicle owners to properly flush their cooling systems and recharge them with fresh antifreeze, without the need substantial mechanical expertise and physical labor, or the need to acquire expensive pumping equipment.